This invention relates to appliances, such as ovens, dishwashers, refrigerators and stoves, which are insulated with fiber mat or fibrous insulation.
A conventional insulation for appliances is fiber insulation, such as fiberglass, polymeric fibers or cellulose fibers. Various problems are associated with the conventional use of such fiber insulation. The fibers are usually provided in the form of mats or batts, which are cut and shaped at the site of assembly of the appliance and taped or plastic film wrapped in place on the appliance. The fiber mats or batts frequently lack dimensional stability and will stretch or tear during installation on the appliance. The loose fibers, which are dislodged from the mats and batts during handling and assembly on the appliance, pose a worker risk ranging from skin irritation to significant health problems, especially with fiberglass insulation.
Various methods have been used to avoid or solve the above problems. Fiber mats and batts have been encapsulated in plastic film bags or pillows. The fiber has been impregnated with binder or resin to form a unitary mass of fiber to prevent loss of individual fibers. However, these method have disadvantages which make them undesirable to use because of loss of insulating value of the mat or batt, or ineffectiveness in actually solving the problem.
There is a need for an efficient, cost effective way to contain fiber insulation in appliance applications.
This invention provides a simple, low cost way of containing fiber insulation for application to appliances. Consequently, this invention provides a combination of an appliance, fiber insulation layer applied to the exterior surface of a wall of the appliance and a metal foil layer adhesively bonded to the outside of the fiber layer. This combination is conveniently formed by adhesively bonding the fiber layer to the metal foil, then applying the fiber layer to the exterior surface of the wall of the appliance such that in the final assembly the fiber layer is contained between the surface of the wall of the appliance and the metal foil layer. The metal foil layer with the fiber layer adhesively bonded to it, provides a dimensionally stable insulating material that can be cut to shape or pre-cut in a controlled environment to the desired shape and size for a particular appliance application.
In another aspect this invention optionally provides the above combination and assembly, but with additional layers of metal foils and/or additional layer of fiber insulation. Depending on the particular application and insulation value needed in a particular appliance, the fiber layer may have a metal foil layer adhesively bonded to both sides of the fiber layer. In this embodiment, one metal foil layer on one side of the fiber layer is positioned on the surface of the wall of the appliance and the other metal foil layer is adhesively bonded to the other side of the fiber layer. This embodiment provides a means to enclose the fiber insulation between the metal foil layers before assembly on the appliance.